Twist is a mechanical thing with the same limits for each twist the combination of bullet length and bullet speed are the controlling factors.
There is also the fact that people try what is available there are not many that make there own jacketed bullets and lead bullets have very specific limits.
One thing that people do not realize is that many bullets that are close to the optimum length can have as many as 3 different loads where they will shoot accurately, it has to do with barrel whip and when the barrel come back to strait on.